U.S. patent application number 13/122668 was filed with the patent office on 2011-07-28 for handpiece for dental or surgical use.
This patent application is currently assigned to BIEN-AIR HOLDING S.A.. Invention is credited to Luc Maitre.
Application Number | 20110183286 13/122668 |
Document ID | / |
Family ID | 41402581 |
Filed Date | 2011-07-28 |
United States Patent
Application |
20110183286 |
Kind Code |
A1 |
Maitre; Luc |
July 28, 2011 |
HANDPIECE FOR DENTAL OR SURGICAL USE
Abstract
Handpiece for dental or surgical use including fixed (2)
components and moveable components, characterized in that at least
some of said fixed (2) and/or moveable components are made from a
composite material resulting from the association of at least two
distinct basic materials, namely a matrix and a reinforcing agent,
the composite material being deposited in one or several
layers.
Inventors: |
Maitre; Luc; (Epauvillers,
CH) |
Assignee: |
BIEN-AIR HOLDING S.A.
Bienne 6
CH
|
Family ID: |
41402581 |
Appl. No.: |
13/122668 |
Filed: |
October 6, 2009 |
PCT Filed: |
October 6, 2009 |
PCT NO: |
PCT/EP2009/062937 |
371 Date: |
April 5, 2011 |
Current U.S.
Class: |
433/82 ;
428/34.1 |
Current CPC
Class: |
A61C 1/10 20130101; Y10T
428/13 20150115; A61B 2017/00544 20130101; A61C 2201/00 20130101;
A61C 1/12 20130101; A61B 17/1622 20130101; A61B 2017/00831
20130101; A61C 1/08 20130101; B29C 33/505 20130101 |
Class at
Publication: |
433/82 ;
428/34.1 |
International
Class: |
A61C 1/12 20060101
A61C001/12; B32B 1/08 20060101 B32B001/08; B32B 27/04 20060101
B32B027/04; B32B 27/38 20060101 B32B027/38; A61C 1/08 20060101
A61C001/08 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 7, 2008 |
CH |
01598/08 |
Claims
1.-6. (canceled)
7. A handpiece for dental or surgical use including fixed
components and moveable components, wherein the fixed components
include the head and the handle of said handpieces and the fixed or
rotating connector parts for connecting said handpieces to a supply
and control unit, at least some of the fixed components are made
from a composite material resulting from the association of at
least two distinct basic materials, namely an epoxy resin matrix
and a reinforcing agent in the form of a carbon fibre mat, the
composite material being deposited in one or several layers.
8. The handpiece according to claim 7, wherein the matrix is an
epoxy resin with two components.
9. The handpiece according to claim 7, wherein the handle has
smooth surfaces and matt surfaces.
10. The handpiece according to claim 8, wherein the handle has
smooth surfaces and matt surfaces.
11. A core for implementing a method of manufacturing fixed and/or
moveable components for a dental or surgical handpiece, said
components being made from a composite material resulting from the
association of at least two distinct basic materials, namely a
matrix and a reinforcing agent, wherein the core is placed in a
mould for moulding said components, and the core is wherein it
includes receiving means in which one or several conduits will be
housed, prior to moulding, for the air and/or water supply and/or a
light guide supplying light to the head of the handpiece.
12. The core according to claim 11, wherein the receiving means is
grooves.
Description
[0001] The present invention concerns a handpiece for dental or
surgical use. More specifically, the present invention concerns an
instrument of this type for dental or surgical use, wherein the
body is made of a light, resistant material.
[0002] There are essentially two families of hand held instruments
for dental or surgical use. The first of these families groups
together what are called turbines, i.e. instruments whose tool, for
example a bur, is coupled to a motor driven by compressed air. This
type of motor can rotate at several hundreds of thousands of
revolutions per minute with an air temperature typically on the
order of 2.5 to 3 bars. The turbine includes a handle which enables
the user to hold the instrument in his hand. The handle is
conventionally connected to an electric power and fluid supply
(air, water) unit via a connector and a flexible tube.
[0003] The second family of instruments for dental or surgical use
groups together what are known as handpieces and contra-angles.
Handpieces and contra-angles essentially differ in that the body of
a handpiece is substantially straight while the contra-angle body
forms an angle at some point on the length thereof. Otherwise,
these two types of instruments are very similar. An electric motor,
housed in the handle of the handpiece or contra-angle and capable
of rotating at several tens of thousands of revolutions per minute,
is connected via a tube with a fixed or rotating connector to the
supply unit.
[0004] For the sake of convenience, the instruments for dental or
surgical use described above will be referred to hereinafter by the
generic term "handpiece", in the knowledge that this term covers
not just handpieces but also turbines and contra-angles.
[0005] Handpieces essentially comprise a handle which enables them
to be hand-held and a head which carries the tool. These elements
are conventionally manufactured from a brass or stainless steel
bar. They have extremely complex external and internal shapes,
which are expensive and time-consuming to machine (cutting,
piercing, threading, stamping etc.) and require sophisticated
machine-tools which may include up to eight different machine axes.
Moreover, however sophisticated the machine-tools used, there is
always a limit imposed by the shapes that these elements can be
given.
[0006] It will also be noted that the materials used--brass or
stainless steel--have advantages but also drawbacks. Brass, for
example, is a material greatly appreciated by manufacturers because
it is easy to machine. However, brass has the drawback of oxidising
easily and thus has to undergo surface treatments via the
deposition of layers of corrosion resistant materials. These
relatively fragile layers tend to wear and scratch easily, and can
expose the underlying brass layer in places, which gives users the
impression that the instrument is of mediocre quality. Further,
certain layers contain nickel, which, on contact, may cause users
to develop allergies when these layers are exposed.
[0007] Conversely, stainless steel is, by definition, a material
with good corrosion resistance and therefore does not require any
specific treatment from this point of view. Moreover, stainless
steel is lighter than brass and can thus allow producing handpieces
that are less heavy in the user's hand, thus reducing the fatigue
that the latter may feel after several hours of work. However,
stainless steel has the drawback of being difficult to machine.
[0008] To overcome these problems, certain handpiece components
(elements for connecting handpieces to the supply and control unit,
insulating elements for electrical connectors, turbine blades etc.)
have already been made by injecting plastic materials. Certain of
the plastic materials used are biocompatible, which can allow
producing components that will enter into contact with the user or
patient. Moreover, the injection of plastic materials means that
shapes are obtainable that would be difficult or impossible to
obtain by machining brass or stainless steel pieces. The shapes
that can be obtained by injecting a plastic material are, however,
limited by the problems raised by removing the core or insert after
the plastic material has cooled. For example, it would not be
possible to remove the core from a part with a generally
cylindrical shape, which would be bent locally. Moreover, the range
of plastic material available to the manufacturer is very limited
because of the lack of resistance of most of these materials to the
sterilising cycles to which dental or surgical instruments are
subjected. Finally, as a general rule, plastic materials do not
enjoy a good image with users.
[0009] Whether the handpieces are made of brass or stainless steel
or by injecting plastic material, they are perfectly rigid and thus
transmit all of the vibrations generated during operation, which is
tiring for the user and makes his movements imprecise.
[0010] There was therefore a need in the state of the art for a
material that could combine the advantages of plastic materials
(lightness, freedom as to shape, precision, repeatability and
rapidity of injection) and metallic materials (longevity,
mechanical resistance), and yet have properties of absorption for
the vibrations generated by operation of the handpieces.
[0011] It is an object of the present invention to respond to this
expectation by providing a handpiece for dental or surgical use
including fixed components and moveable components, characterized
in that at least some of these fixed and/or moveable components are
made of a composite material resulting from the association of at
least two distinct basic materials, namely an epoxy resin matrix
and a reinforcing agent.
[0012] The matrix is obtained using an epoxy resin with two
components and the reinforcing agent is selected from the group
containing fibres or particles of carbon, glass, boron, kevlar,
ceramic, aramid, nylon, steel or tungsten.
[0013] In a piece made of composite material, the epoxy resin
matrix and reinforcing agent are placed in intimate contact on a
macroscopic scale, the matrix giving the piece the desired shape
and transmitting to the reinforcing agent (fibres or particles) the
mechanical stresses to which said piece is subjected, which
improves certain features of the reinforcing agent material.
[0014] A significant cause of fatigue in users of surgical or
dental handpieces is connected to the vibrations generated by the
operation of said handpieces. It has been realised that, in
addition to being very resistant, epoxy resin handpiece handles
have a degree of flexibility and are entirely able to absorb the
vibrations generated by the operation of the handpieces. A
handpiece fitted with this type of handle, for example made of
carbon fibre, will thus vibrate less, which means the user gets
less tired and makes more precise movements.
[0015] The fixed components of a surgical or dental handpiece
include, in particular, the head and handle of such handpieces and
the fixed or rotating connector parts for connecting the handpieces
to a supply and control unit, better known simply as a "unit". The
moveable components include, amongst others, the turbine motors,
the drivers and more generally the kinematic transmission chains
for transmitting the motor torque to the tools and certain
components of the handpieces or contra-angles.
[0016] Plastic materials appeared to open up promising perspectives
within the field of manufacturing components for dental or surgical
handpieces, but the limits of injecting such materials were very
soon reached. Indeed, to be able to inject a plastic piece, on the
one hand, a mould must be available to take the external shapes of
the piece to be injected, and on the other hand, a rigid core or
insert, which defines the internal shapes of said piece. After the
plastic material has been injected into the volume left free
between the mould and the core, the piece is cooled and removed
from the mould and the core is taken out. It is this last step of
removing the core which presents a problem. Indeed, it is not
possible to envisage making pieces that have, for example, a
reduced diameter or bent portion in places, since, in such case, it
would not be possible to remove the rigid core after the piece has
cooled. There is a need in the state of the art for handpieces with
novelty shapes or ergonomic shapes which has not been satisfied to
date, given that the shapes accessible by machining brass or
stainless steel pieces or by plastic injection are essentially
cylindrical shapes.
[0017] The present invention can overcome all of these limitations
by teaching that surgical or dental handpiece components, such as
heads or handles, can be made of epoxy resin. Indeed, the
determining element in the technique of manufacturing epoxy resin
components lies in the use of a core or insert made of a
compressible material, such as silicon. More specifically, if one
wishes, for example, to make a carbon fibre piece, the compressible
core that defines the internal shapes of the piece to be made is
covered in a carbon fibre mat or plaiting, then introduced into a
mould which takes the external shapes of the piece to be
manufactured. Epoxy resin is then introduced into the gap left free
between the mould and the core and impregnates the carbon fibre.
When the resin has hardened, the piece is taken out of the mould
and the core is removed. Since the core is compressible, it can be
deformed and thus pass without any difficulty over any point where
the piece has, for example, a narrowed area or bent portion. Making
handpiece components for surgical or dental use from a composite
material thus eliminates almost all constraints in terms of the
shape of the pieces to be made, and handpieces can thus be proposed
with, for example, handles having novelty shapes or ergonomic
handles that are easier to hold in the hand. It will be noted,
however, that manufacturing a carbon fibre handpiece handle by
means of the technique described above requires much more care and
attention than manufacturing a handle, for example, by plastic
injection. The step during which the core is coated in the carbon
fibre mat or plaiting requires especially great care. Indeed, care
must be taken to ensure that the carbon fibre mat matches the
shapes of the core as closely as possible, so as to respect not
only the internal geometry of the resulting piece, but also the
thickness of the gap which separates the core coated in the mat
from the mould and which determines the thickness of the resulting
piece and thus conformity with the dimensions.
[0018] Making handpieces from composite material also allows weight
savings to be made. Thus, for example, a handle made of brass which
weights 14 g will weigh no more than 4 g when it is made of carbon
fibre. A weight gain of 10 g is thus achieved, which represents a
gain of around 15% on the total weight of an instrument, which is
typically around 70 g. It will easily be understood that a lighter
handpiece is less tiring for the user, who sometimes has to hold it
in his hand for several hours a day.
[0019] The invention also concerns a core for implementing a method
of manufacturing fixed and/or moveable components for a dental or
surgical handpiece, said components being made from a composite
material resulting from the association of at least two distinct
basic materials, namely an epoxy resin matrix and a reinforcing
agent. In said method, the core is introduced into a mould for
moulding said components, and the core is characterized in that it
includes receiving means in which one or several conduits will be
housed, prior to moulding, for the air and/or water inlet and/or a
light guide supplying light to the handpiece head. Preferably, the
receiving means is grooves which will house, for example, conduits
for the air and water supply, and a glass bar or optic fibre bundle
for supplying light to the turbine head. As a result of this
technique, pieces with very complex shapes can be made without any
need to worry about how the various conduits and optical guides
could be manually introduced into an equivalent handpiece made of
brass of stainless steel. After the various conduits and light
guides have been inserted into the grooves, the core is wrapped in
a mat, for example, of carbon fibres, and the whole is then placed
in the mould. The fibre mat is then impregnated by means of an
epoxy resin which is allowed to harden, and then the piece is
removed from the mould. The conduits and optical guides are then
trapped in the resin.
[0020] Other features and advantages of the invention will appear
more clearly from the following detailed description of an
embodiment of the handpiece according to the invention, this
example being given solely by way of non-limiting illustration with
reference to the annexed drawing, in which:
[0021] FIG. 1 is a cross-sectional view of a turbine type handpiece
according to the present invention;
[0022] FIG. 2 shows a longitudinal cross-section of a mould
illustrating the method of manufacturing a carbon fibre handle
according to the invention;
[0023] FIG. 3 is a perspective view of an alternative embodiment of
a core for manufacturing a carbon fibre handle;
[0024] The present invention proceeds from the general inventive
idea that consists in making at least some components of a
handpiece for dental or surgical use from a composite material
resulting from the association of at least two distinct basic
materials, namely an epoxy resin matrix and a reinforcing agent.
Most of the handpieces available on the market are made of brass or
stainless steel, and very rarely by injecting a plastic material.
These handpieces are perfectly rigid and thus transmit all of the
vibrations generated during operation, which is tiring for the user
and makes his movements imprecise. It was realised that handpiece
handles made from epoxy resin have a degree of flexibility and are
entirely capable of absorbing vibrations, which is more restful for
the user and which enables him to improve the precision of his
movements. Further, a handpiece wherein, for example, the handle is
made of epoxy resin is more resistant and lighter. Finally, making
a handpiece handle from epoxy resin means that novelty shapes can
be produced, or ergonomic shapes making it easier to hold the
handle in the hand. Indeed, the mould core or insert is made of a
compressible elastomeric material, which means it can be removed
after moulding, even if the handle has reductions in diameter or
bent shapes in places, since the core will be able to be
compressed, passing over areas of reduced diameter.
[0025] For the sake of clarity, the present invention will be
described with reference to the embodiment of a handpiece handle
for dental or surgical use made from carbon fibre impregnated with
epoxy resin. It should, however, be understood that this example is
given purely for non-limiting, illustrative purposes and that,
according to a variant of the invention, this handle could be made
in a similar manner using glass, boron, kevlar, ceramic, aramid,
nylon, steel or tungsten fibres impregnated with epoxy resin.
Likewise, according to another variant of the invention, the fixed
and/or moveable components of a handpiece of the invention may be
made using one or several layers of impregnated fibres.
[0026] FIG. 1 is a longitudinal cross-section of a turbine.
Designated as a whole by the general reference number 1, this
turbine includes a handle 2 made from carbon fibre to which there
are connected a head 4 and a nozzle 6 for mounting a receptacle 8
to which a quick release coupling (not shown) will be connected for
the supply of working fluids (air and water) and electricity. Head
4 and nozzle 6 could, for example, be made of stainless steel to
contrast with the black colour of the carbon fibre and thus provide
an advantageous aesthetic effect at ends 8a and 8b of handle 2 to
which they are connected.
[0027] An example implementation of the method of manufacturing a
carbon fibre handle according to the invention is given with
reference to FIG. 2 annexed to this patent application. A core or
insert 10, made from a compressible material such as silicon, and
whose external shapes match the desired internal profile of the
handle to be manufactured is covered in a carbon fibre mat 12. Core
10, thus wrapped in carbon fibre mat 12 is arranged inside a mould
16 whose inner surface matches the desired external shape of handle
2 to be manufactured. The thickness of carbon fibre mat 12 is
typically three tenths of a millimetre and the play between core 10
and mould 16 is around a tenth of a millimetre. Thus an epoxy
resin, which will impregnate carbon fibre mat 12, is moved into the
empty space between core 10 and mould 16. It will be clear, that,
for example, a glass or boron fibre mat may equally well be used
instead of the carbon fibre mat.
[0028] When the epoxy resin has hardened, the part thereby obtained
is removed from the mould. Since core 10 is compressible, it is
able to deform to pass through places where handle 2 is bent or has
a reduced diameter. The surface state of the handle 2 thereby
obtained will depend upon the inner surface state of mould 16. If
the inner surface of mould 16 has a mirror-polished state, the
surface of handle 2 will be smooth and shiny. Conversely, if the
inner surface of mould 16 has rough areas in places, the surface of
handle 2 will have a rough, matt surface in corresponding places.
These surfaces may, for example, define for the user areas where
handle 2 can be gripped.
[0029] According to a variant of the invention, receiving means is
provided on core 10, for example in the form of grooves which will
house, for example, conduits for the air and water supply, and a
glass bar or optical fibre bundle for supplying light to the head 4
of turbine 1. When the various conduits and optical guides have
been inserted in grooves 18, the core 10 is fitted into carbon
fibre mat 12. The conduits and light guides do not interfere with
the engagement of carbon fibre mat 12 given that the latter can be
stretched to up to two times its normal size. The series of
subsequent operations is identical to that described above. Core 10
with its carbon fibre mat 12 is placed in a mould which is then
closed. The fibres are impregnated with an epoxy resin which is
allowed to harden, then the part is removed from the mould and cut
to the desired shape and dimensions. Finally, the core is removed.
The air and/or water conduits and the optical guide are trapped
inside the epoxy resin. As a result of this technique, handpieces
with very complex shapes can be manufactured without any need to
worry about how the various conduits and optical guides could be
manually inserted into an equivalent handpiece made of brass of
stainless steel.
* * * * *